diff options
Diffstat (limited to 'arch/m68k/coldfire/pci.c')
| -rw-r--r-- | arch/m68k/coldfire/pci.c | 259 |
1 files changed, 259 insertions, 0 deletions
diff --git a/arch/m68k/coldfire/pci.c b/arch/m68k/coldfire/pci.c new file mode 100644 index 000000000..ceb5775b8 --- /dev/null +++ b/arch/m68k/coldfire/pci.c @@ -0,0 +1,259 @@ +/* + * pci.c -- PCI bus support for ColdFire processors + * + * (C) Copyright 2012, Greg Ungerer <gerg@uclinux.com> + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file COPYING in the main directory of this archive + * for more details. + */ + +#include <linux/types.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/io.h> +#include <linux/pci.h> +#include <linux/delay.h> +#include <asm/coldfire.h> +#include <asm/mcfsim.h> +#include <asm/m54xxpci.h> + +/* + * Memory and IO mappings. We use a 1:1 mapping for local host memory to + * PCI bus memory (no reason not to really). IO space is mapped in its own + * separate address region. The device configuration space is mapped over + * the IO map space when we enable it in the PCICAR register. + */ +static struct pci_bus *rootbus; +static unsigned long iospace; + +/* + * We need to be careful probing on bus 0 (directly connected to host + * bridge). We should only access the well defined possible devices in + * use, ignore aliases and the like. + */ +static unsigned char mcf_host_slot2sid[32] = { + 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, + 0, 1, 2, 0, 3, 4, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, +}; + +static unsigned char mcf_host_irq[] = { + 0, 69, 69, 71, 71, +}; + +/* + * Configuration space access functions. Configuration space access is + * through the IO mapping window, enabling it via the PCICAR register. + */ +static unsigned long mcf_mk_pcicar(int bus, unsigned int devfn, int where) +{ + return (bus << PCICAR_BUSN) | (devfn << PCICAR_DEVFNN) | (where & 0xfc); +} + +static int mcf_pci_readconfig(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 *value) +{ + unsigned long addr; + + *value = 0xffffffff; + + if (bus->number == 0) { + if (mcf_host_slot2sid[PCI_SLOT(devfn)] == 0) + return PCIBIOS_SUCCESSFUL; + } + + addr = mcf_mk_pcicar(bus->number, devfn, where); + __raw_writel(PCICAR_E | addr, PCICAR); + __raw_readl(PCICAR); + addr = iospace + (where & 0x3); + + switch (size) { + case 1: + *value = __raw_readb(addr); + break; + case 2: + *value = le16_to_cpu(__raw_readw(addr)); + break; + default: + *value = le32_to_cpu(__raw_readl(addr)); + break; + } + + __raw_writel(0, PCICAR); + __raw_readl(PCICAR); + return PCIBIOS_SUCCESSFUL; +} + +static int mcf_pci_writeconfig(struct pci_bus *bus, unsigned int devfn, + int where, int size, u32 value) +{ + unsigned long addr; + + if (bus->number == 0) { + if (mcf_host_slot2sid[PCI_SLOT(devfn)] == 0) + return PCIBIOS_SUCCESSFUL; + } + + addr = mcf_mk_pcicar(bus->number, devfn, where); + __raw_writel(PCICAR_E | addr, PCICAR); + __raw_readl(PCICAR); + addr = iospace + (where & 0x3); + + switch (size) { + case 1: + __raw_writeb(value, addr); + break; + case 2: + __raw_writew(cpu_to_le16(value), addr); + break; + default: + __raw_writel(cpu_to_le32(value), addr); + break; + } + + __raw_writel(0, PCICAR); + __raw_readl(PCICAR); + return PCIBIOS_SUCCESSFUL; +} + +static struct pci_ops mcf_pci_ops = { + .read = mcf_pci_readconfig, + .write = mcf_pci_writeconfig, +}; + +/* + * Initialize the PCI bus registers, and scan the bus. + */ +static struct resource mcf_pci_mem = { + .name = "PCI Memory space", + .start = PCI_MEM_PA, + .end = PCI_MEM_PA + PCI_MEM_SIZE - 1, + .flags = IORESOURCE_MEM, +}; + +static struct resource mcf_pci_io = { + .name = "PCI IO space", + .start = 0x400, + .end = 0x10000 - 1, + .flags = IORESOURCE_IO, +}; + +static struct resource busn_resource = { + .name = "PCI busn", + .start = 0, + .end = 255, + .flags = IORESOURCE_BUS, +}; + +/* + * Interrupt mapping and setting. + */ +static int mcf_pci_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) +{ + int sid; + + sid = mcf_host_slot2sid[slot]; + if (sid) + return mcf_host_irq[sid]; + return 0; +} + +static int __init mcf_pci_init(void) +{ + struct pci_host_bridge *bridge; + int ret; + + bridge = pci_alloc_host_bridge(0); + if (!bridge) + return -ENOMEM; + + pr_info("ColdFire: PCI bus initialization...\n"); + + /* Reset the external PCI bus */ + __raw_writel(PCIGSCR_RESET, PCIGSCR); + __raw_writel(0, PCITCR); + + request_resource(&iomem_resource, &mcf_pci_mem); + request_resource(&iomem_resource, &mcf_pci_io); + + /* Configure PCI arbiter */ + __raw_writel(PACR_INTMPRI | PACR_INTMINTE | PACR_EXTMPRI(0x1f) | + PACR_EXTMINTE(0x1f), PACR); + + /* Set required multi-function pins for PCI bus use */ + __raw_writew(0x3ff, MCFGPIO_PAR_PCIBG); + __raw_writew(0x3ff, MCFGPIO_PAR_PCIBR); + + /* Set up config space for local host bus controller */ + __raw_writel(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | + PCI_COMMAND_INVALIDATE, PCISCR); + __raw_writel(PCICR1_LT(32) | PCICR1_CL(8), PCICR1); + __raw_writel(0, PCICR2); + + /* + * Set up the initiator windows for memory and IO mapping. + * These give the CPU bus access onto the PCI bus. One for each of + * PCI memory and IO address spaces. + */ + __raw_writel(WXBTAR(PCI_MEM_PA, PCI_MEM_BA, PCI_MEM_SIZE), + PCIIW0BTAR); + __raw_writel(WXBTAR(PCI_IO_PA, PCI_IO_BA, PCI_IO_SIZE), + PCIIW1BTAR); + __raw_writel(PCIIWCR_W0_MEM /*| PCIIWCR_W0_MRDL*/ | PCIIWCR_W0_E | + PCIIWCR_W1_IO | PCIIWCR_W1_E, PCIIWCR); + + /* + * Set up the target windows for access from the PCI bus back to the + * CPU bus. All we need is access to system RAM (for mastering). + */ + __raw_writel(CONFIG_RAMBASE, PCIBAR1); + __raw_writel(CONFIG_RAMBASE | PCITBATR1_E, PCITBATR1); + + /* Keep a virtual mapping to IO/config space active */ + iospace = (unsigned long) ioremap(PCI_IO_PA, PCI_IO_SIZE); + if (iospace == 0) { + pci_free_host_bridge(bridge); + return -ENODEV; + } + pr_info("Coldfire: PCI IO/config window mapped to 0x%x\n", + (u32) iospace); + + /* Turn of PCI reset, and wait for devices to settle */ + __raw_writel(0, PCIGSCR); + set_current_state(TASK_UNINTERRUPTIBLE); + schedule_timeout(msecs_to_jiffies(200)); + + + pci_add_resource(&bridge->windows, &ioport_resource); + pci_add_resource(&bridge->windows, &iomem_resource); + pci_add_resource(&bridge->windows, &busn_resource); + bridge->dev.parent = NULL; + bridge->sysdata = NULL; + bridge->busnr = 0; + bridge->ops = &mcf_pci_ops; + bridge->swizzle_irq = pci_common_swizzle; + bridge->map_irq = mcf_pci_map_irq; + + ret = pci_scan_root_bus_bridge(bridge); + if (ret) { + pci_free_host_bridge(bridge); + return ret; + } + + rootbus = bridge->bus; + + rootbus->resource[0] = &mcf_pci_io; + rootbus->resource[1] = &mcf_pci_mem; + + pci_bus_size_bridges(rootbus); + pci_bus_assign_resources(rootbus); + pci_bus_add_devices(rootbus); + return 0; +} + +subsys_initcall(mcf_pci_init); |